Neural proliferation after injury

Miami, Florida -

Although it is reported that the brain can repair itself after injury, detailed examination of this is still somewhat lacking. In a nicely designed study (Urrea et al. Widespread cellular proliferation and focal neurogenesis after traumatic brain injury in the rat. Restor Neurol Neurosci. 2007;25(1):65-77), proliferation of various brain areas was assessed following traumatic injury.

BRDU was administered to rats prior to brain injury so as to be able to track proliferating cells. Brain injury was induced by fluid percussion. Assessment was made by euthanizing the rats and performing immunohistochemistry to detect both BRDU staining, as well as neurons, astrocytes, oligodendrocytes, and macrophage/microglia. Assessments were made as soon as 3 hours after injury and all the way to 14 days.

At early timepoints post injury proliferation was limited to the subventricular zone of the hemisphere that was injured. At subsequent timepoints, all the way to 14 days post injury, proliferation was observed in the hippocampus, cerebral cortex, and some contralateral areas. At the cellular level, proliferation was observed in neurons but primarily in glial cells. Profound neurogenesis was observed in the granular cell layer of the hippocampus.

Since damage to the hippocampus has been associated with inability to form new memories, it would be interesting to see whether stem cell therapy can reverse this.